Phone call tech support (Twin Reish) blows HT

[Reeltarded]

Friend called from a tour. Twin Reverb had a broken power tube that went unnoticed until it was turned on and did a little smoke trick.

He replaced the tubes, and the HT, hoping it was just the open tube smoking. I have a pic on my phone of the getters from the broken tube melted together.

Advice for him? He knows how to solder, but doesn't have a large compliment of tools on hand.

It does work with a new fuse, for about 1 minute out of standby.

Anything would help. His back up amp sounds terrible.

[selloutrr]

I've had this happen a few times across the bench.
Assuming nothing is burned inside amp.
the PCB solder points on the tube socket heated up when the tube died causing a cold solder. resolder the tube socket, filter caps, and rectifier. should be good as new with new tubes after the bias. if they are GT fender he might get lucky and just get to drop in the "#" on the tube and be ok as far as bias.

[Gaz]

I've had the same issue on those. Even though the sockets are technically chassis mounted, the pins reach all the way to the PCB board. I swear there was just never enough solder to begin with. I've seen all sorts of light shows inside tubes because of intermittent connection to the socket. One thing he can do is simply look at the tubes while amp is on to see if anything goes crazy in there (i.s red plating, flashing purple light) before the fuse blows, which can be indicative of that problem. Tubes are pretty tough, but I'd hate to see him blow a new quad playing techie.

[Gibsonman63]

Conductive carbon traces on the tube socket?

[selloutrr]

the amps are assembled just south of the Arizona border in a little town Fender literally own's. The amps are assembled by little old ladies. The wave solder machine quality control is pretty sketchy. They miss all sorts of solder contacts. I've seen them miss solder joints entirely amps working for years with just the luck of pressure keeping the wires making contact.

The quickest way to fix any RI fender is to resolder the PCB and do a wire trace and touch up every solder point. While you are in the amp look for burn marks and clean the sockets, tighten bolts, and just do a general service. 99% of the time the amp will fire up and be better then it was new.

It's to bad Fender has such a low quality control. But it keeps tech's in business. The total time to go over the amp from start to playable is about 2.5hrs.

[Reeltarded]

Will check this stuff out myself, as he's back tomorrow..

I wish I knew more about things people think I know more about. I do appreciate the pointers! I hate the flavor of electricity..

It tastes like metal, with electricity in it.

[selloutrr]

good news fender has bleeder resistors

[Reeltarded]

Ahh... I do my best to resist bleeding. Works. (sometimes)

[backpack]

If there is a light show under the socket he needs to pull the board and asess the damage. I have had tubes do nasty things when they give up the ghost.

[Reeltarded]

Update: What resistor is blk, blk, blk, blk? Is that like a 0ohm Carbon?

Yes. Yes it is.

1.5k and 470s on tube sockets.. FOOOF. lol

[Reeltarded]

Should I be replacing all these with the same values?

[Gibsonman63]

Same value, but higher wattage metal film on the 470 ohm resistors. I think I used 3W on some of mine. 1K is supposed to give better touch sensativity, but I haven't tried it yet. I would also use metal film on the 1k5 resistors just because of the heat over the socket.